[itsme]

Motivated by https://zubersoft.com/mobilesheets/forum...12075.html I investigated ABC handling (MobileSheets 3.9.3 on Win10)
I documented most of the steps as that might become a frequent workflow for me as soon as ABC integration in MobileSheets works  fine.

I started with an existing score in MuseScore 3.6.2 and used the plugin ABCImpExp V1.1 to create an ABC file.
Both FreudeSchoenerGoetterfunken_ABCImpExp_ANSI.abc and FreudeSchoenerGoetterfunken_ABCImpExp_UTF8.abc look fine in EasyABC and could be imported into MobileSheets without errors. 
When I try to open any of them in MobileSheets it shows the endless blue circle as reported and is not displayed. So the encoding is not (no more) the cause of that issue.

Just renaming the file to FreudeSchoenerGoetterfunken_ABCImpExp_1.pro did not help. FreudeSchoenerGoetterfunken_ABCImpExp_1.pro can be imported and  MobileSheets displays the ABC code as text - not unexpected.

In FreudeSchoenerGoetterfunken_ABCImpExp_2.pro I just added {start_of_abc} and {end_of_abc} and it is imported and displayed in MobileSheets correctly!
This is a hint that nothing's wrong with the ABC syntax, assuming MobileSheets uses the same ABC package for ABC files as for ABC code that is embedded into a ChordPro file
It might be a feasable workaround for users that want to use "ABC only" files immediately, already with the released MobileSheets 3.9.3.